linux/drivers/power/generic-adc-battery.c
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   1/*
   2 * Generic battery driver code using IIO
   3 * Copyright (C) 2012, Anish Kumar <anish198519851985@gmail.com>
   4 * based on jz4740-battery.c
   5 * based on s3c_adc_battery.c
   6 *
   7 * This file is subject to the terms and conditions of the GNU General Public
   8 * License.  See the file COPYING in the main directory of this archive for
   9 * more details.
  10 *
  11 */
  12#include <linux/interrupt.h>
  13#include <linux/platform_device.h>
  14#include <linux/power_supply.h>
  15#include <linux/gpio.h>
  16#include <linux/err.h>
  17#include <linux/timer.h>
  18#include <linux/jiffies.h>
  19#include <linux/errno.h>
  20#include <linux/init.h>
  21#include <linux/module.h>
  22#include <linux/slab.h>
  23#include <linux/iio/consumer.h>
  24#include <linux/iio/types.h>
  25#include <linux/power/generic-adc-battery.h>
  26
  27#define JITTER_DEFAULT 10 /* hope 10ms is enough */
  28
  29enum gab_chan_type {
  30        GAB_VOLTAGE = 0,
  31        GAB_CURRENT,
  32        GAB_POWER,
  33        GAB_MAX_CHAN_TYPE
  34};
  35
  36/*
  37 * gab_chan_name suggests the standard channel names for commonly used
  38 * channel types.
  39 */
  40static const char *const gab_chan_name[] = {
  41        [GAB_VOLTAGE]   = "voltage",
  42        [GAB_CURRENT]   = "current",
  43        [GAB_POWER]             = "power",
  44};
  45
  46struct gab {
  47        struct power_supply     psy;
  48        struct iio_channel      *channel[GAB_MAX_CHAN_TYPE];
  49        struct gab_platform_data        *pdata;
  50        struct delayed_work bat_work;
  51        int     level;
  52        int     status;
  53        bool cable_plugged;
  54};
  55
  56static struct gab *to_generic_bat(struct power_supply *psy)
  57{
  58        return container_of(psy, struct gab, psy);
  59}
  60
  61static void gab_ext_power_changed(struct power_supply *psy)
  62{
  63        struct gab *adc_bat = to_generic_bat(psy);
  64
  65        schedule_delayed_work(&adc_bat->bat_work, msecs_to_jiffies(0));
  66}
  67
  68static const enum power_supply_property gab_props[] = {
  69        POWER_SUPPLY_PROP_STATUS,
  70        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
  71        POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN,
  72        POWER_SUPPLY_PROP_CHARGE_NOW,
  73        POWER_SUPPLY_PROP_VOLTAGE_NOW,
  74        POWER_SUPPLY_PROP_CURRENT_NOW,
  75        POWER_SUPPLY_PROP_TECHNOLOGY,
  76        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
  77        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
  78        POWER_SUPPLY_PROP_MODEL_NAME,
  79};
  80
  81/*
  82 * This properties are set based on the received platform data and this
  83 * should correspond one-to-one with enum chan_type.
  84 */
  85static const enum power_supply_property gab_dyn_props[] = {
  86        POWER_SUPPLY_PROP_VOLTAGE_NOW,
  87        POWER_SUPPLY_PROP_CURRENT_NOW,
  88        POWER_SUPPLY_PROP_POWER_NOW,
  89};
  90
  91static bool gab_charge_finished(struct gab *adc_bat)
  92{
  93        struct gab_platform_data *pdata = adc_bat->pdata;
  94        bool ret = gpio_get_value(pdata->gpio_charge_finished);
  95        bool inv = pdata->gpio_inverted;
  96
  97        if (!gpio_is_valid(pdata->gpio_charge_finished))
  98                return false;
  99        return ret ^ inv;
 100}
 101
 102static int gab_get_status(struct gab *adc_bat)
 103{
 104        struct gab_platform_data *pdata = adc_bat->pdata;
 105        struct power_supply_info *bat_info;
 106
 107        bat_info = &pdata->battery_info;
 108        if (adc_bat->level == bat_info->charge_full_design)
 109                return POWER_SUPPLY_STATUS_FULL;
 110        return adc_bat->status;
 111}
 112
 113static enum gab_chan_type gab_prop_to_chan(enum power_supply_property psp)
 114{
 115        switch (psp) {
 116        case POWER_SUPPLY_PROP_POWER_NOW:
 117                return GAB_POWER;
 118        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 119                return GAB_VOLTAGE;
 120        case POWER_SUPPLY_PROP_CURRENT_NOW:
 121                return GAB_CURRENT;
 122        default:
 123                WARN_ON(1);
 124                break;
 125        }
 126        return GAB_POWER;
 127}
 128
 129static int read_channel(struct gab *adc_bat, enum power_supply_property psp,
 130                int *result)
 131{
 132        int ret;
 133        int chan_index;
 134
 135        chan_index = gab_prop_to_chan(psp);
 136        ret = iio_read_channel_processed(adc_bat->channel[chan_index],
 137                        result);
 138        if (ret < 0)
 139                pr_err("read channel error\n");
 140        return ret;
 141}
 142
 143static int gab_get_property(struct power_supply *psy,
 144                enum power_supply_property psp, union power_supply_propval *val)
 145{
 146        struct gab *adc_bat;
 147        struct gab_platform_data *pdata;
 148        struct power_supply_info *bat_info;
 149        int result = 0;
 150        int ret = 0;
 151
 152        adc_bat = to_generic_bat(psy);
 153        if (!adc_bat) {
 154                dev_err(psy->dev, "no battery infos ?!\n");
 155                return -EINVAL;
 156        }
 157        pdata = adc_bat->pdata;
 158        bat_info = &pdata->battery_info;
 159
 160        switch (psp) {
 161        case POWER_SUPPLY_PROP_STATUS:
 162                gab_get_status(adc_bat);
 163                break;
 164        case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
 165                val->intval = 0;
 166                break;
 167        case POWER_SUPPLY_PROP_CHARGE_NOW:
 168                val->intval = pdata->cal_charge(result);
 169                break;
 170        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 171        case POWER_SUPPLY_PROP_CURRENT_NOW:
 172        case POWER_SUPPLY_PROP_POWER_NOW:
 173                ret = read_channel(adc_bat, psp, &result);
 174                if (ret < 0)
 175                        goto err;
 176                val->intval = result;
 177                break;
 178        case POWER_SUPPLY_PROP_TECHNOLOGY:
 179                val->intval = bat_info->technology;
 180                break;
 181        case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
 182                val->intval = bat_info->voltage_min_design;
 183                break;
 184        case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 185                val->intval = bat_info->voltage_max_design;
 186                break;
 187        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 188                val->intval = bat_info->charge_full_design;
 189                break;
 190        case POWER_SUPPLY_PROP_MODEL_NAME:
 191                val->strval = bat_info->name;
 192                break;
 193        default:
 194                return -EINVAL;
 195        }
 196err:
 197        return ret;
 198}
 199
 200static void gab_work(struct work_struct *work)
 201{
 202        struct gab *adc_bat;
 203        struct gab_platform_data *pdata;
 204        struct delayed_work *delayed_work;
 205        bool is_plugged;
 206        int status;
 207
 208        delayed_work = container_of(work, struct delayed_work, work);
 209        adc_bat = container_of(delayed_work, struct gab, bat_work);
 210        pdata = adc_bat->pdata;
 211        status = adc_bat->status;
 212
 213        is_plugged = power_supply_am_i_supplied(&adc_bat->psy);
 214        adc_bat->cable_plugged = is_plugged;
 215
 216        if (!is_plugged)
 217                adc_bat->status =  POWER_SUPPLY_STATUS_DISCHARGING;
 218        else if (gab_charge_finished(adc_bat))
 219                adc_bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 220        else
 221                adc_bat->status = POWER_SUPPLY_STATUS_CHARGING;
 222
 223        if (status != adc_bat->status)
 224                power_supply_changed(&adc_bat->psy);
 225}
 226
 227static irqreturn_t gab_charged(int irq, void *dev_id)
 228{
 229        struct gab *adc_bat = dev_id;
 230        struct gab_platform_data *pdata = adc_bat->pdata;
 231        int delay;
 232
 233        delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
 234        schedule_delayed_work(&adc_bat->bat_work,
 235                        msecs_to_jiffies(delay));
 236        return IRQ_HANDLED;
 237}
 238
 239static int gab_probe(struct platform_device *pdev)
 240{
 241        struct gab *adc_bat;
 242        struct power_supply *psy;
 243        struct gab_platform_data *pdata = pdev->dev.platform_data;
 244        enum power_supply_property *properties;
 245        int ret = 0;
 246        int chan;
 247        int index = 0;
 248
 249        adc_bat = devm_kzalloc(&pdev->dev, sizeof(*adc_bat), GFP_KERNEL);
 250        if (!adc_bat) {
 251                dev_err(&pdev->dev, "failed to allocate memory\n");
 252                return -ENOMEM;
 253        }
 254
 255        psy = &adc_bat->psy;
 256        psy->name = pdata->battery_info.name;
 257
 258        /* bootup default values for the battery */
 259        adc_bat->cable_plugged = false;
 260        adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
 261        psy->type = POWER_SUPPLY_TYPE_BATTERY;
 262        psy->get_property = gab_get_property;
 263        psy->external_power_changed = gab_ext_power_changed;
 264        adc_bat->pdata = pdata;
 265
 266        /*
 267         * copying the static properties and allocating extra memory for holding
 268         * the extra configurable properties received from platform data.
 269         */
 270        psy->properties = kcalloc(ARRAY_SIZE(gab_props) +
 271                                        ARRAY_SIZE(gab_chan_name),
 272                                        sizeof(*psy->properties), GFP_KERNEL);
 273        if (!psy->properties) {
 274                ret = -ENOMEM;
 275                goto first_mem_fail;
 276        }
 277
 278        memcpy(psy->properties, gab_props, sizeof(gab_props));
 279        properties = (enum power_supply_property *)
 280                                ((char *)psy->properties + sizeof(gab_props));
 281
 282        /*
 283         * getting channel from iio and copying the battery properties
 284         * based on the channel supported by consumer device.
 285         */
 286        for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
 287                adc_bat->channel[chan] = iio_channel_get(&pdev->dev,
 288                                                         gab_chan_name[chan]);
 289                if (IS_ERR(adc_bat->channel[chan])) {
 290                        ret = PTR_ERR(adc_bat->channel[chan]);
 291                        adc_bat->channel[chan] = NULL;
 292                } else {
 293                        /* copying properties for supported channels only */
 294                        memcpy(properties + sizeof(*(psy->properties)) * index,
 295                                        &gab_dyn_props[chan],
 296                                        sizeof(gab_dyn_props[chan]));
 297                        index++;
 298                }
 299        }
 300
 301        /* none of the channels are supported so let's bail out */
 302        if (index == ARRAY_SIZE(gab_chan_name))
 303                goto second_mem_fail;
 304
 305        /*
 306         * Total number of properties is equal to static properties
 307         * plus the dynamic properties.Some properties may not be set
 308         * as come channels may be not be supported by the device.So
 309         * we need to take care of that.
 310         */
 311        psy->num_properties = ARRAY_SIZE(gab_props) + index;
 312
 313        ret = power_supply_register(&pdev->dev, psy);
 314        if (ret)
 315                goto err_reg_fail;
 316
 317        INIT_DELAYED_WORK(&adc_bat->bat_work, gab_work);
 318
 319        if (gpio_is_valid(pdata->gpio_charge_finished)) {
 320                int irq;
 321                ret = gpio_request(pdata->gpio_charge_finished, "charged");
 322                if (ret)
 323                        goto gpio_req_fail;
 324
 325                irq = gpio_to_irq(pdata->gpio_charge_finished);
 326                ret = request_any_context_irq(irq, gab_charged,
 327                                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 328                                "battery charged", adc_bat);
 329                if (ret < 0)
 330                        goto err_gpio;
 331        }
 332
 333        platform_set_drvdata(pdev, adc_bat);
 334
 335        /* Schedule timer to check current status */
 336        schedule_delayed_work(&adc_bat->bat_work,
 337                        msecs_to_jiffies(0));
 338        return 0;
 339
 340err_gpio:
 341        gpio_free(pdata->gpio_charge_finished);
 342gpio_req_fail:
 343        power_supply_unregister(psy);
 344err_reg_fail:
 345        for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
 346                if (adc_bat->channel[chan])
 347                        iio_channel_release(adc_bat->channel[chan]);
 348        }
 349second_mem_fail:
 350        kfree(psy->properties);
 351first_mem_fail:
 352        return ret;
 353}
 354
 355static int gab_remove(struct platform_device *pdev)
 356{
 357        int chan;
 358        struct gab *adc_bat = platform_get_drvdata(pdev);
 359        struct gab_platform_data *pdata = adc_bat->pdata;
 360
 361        power_supply_unregister(&adc_bat->psy);
 362
 363        if (gpio_is_valid(pdata->gpio_charge_finished)) {
 364                free_irq(gpio_to_irq(pdata->gpio_charge_finished), adc_bat);
 365                gpio_free(pdata->gpio_charge_finished);
 366        }
 367
 368        for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
 369                if (adc_bat->channel[chan])
 370                        iio_channel_release(adc_bat->channel[chan]);
 371        }
 372
 373        kfree(adc_bat->psy.properties);
 374        cancel_delayed_work(&adc_bat->bat_work);
 375        return 0;
 376}
 377
 378#ifdef CONFIG_PM
 379static int gab_suspend(struct device *dev)
 380{
 381        struct gab *adc_bat = dev_get_drvdata(dev);
 382
 383        cancel_delayed_work_sync(&adc_bat->bat_work);
 384        adc_bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
 385        return 0;
 386}
 387
 388static int gab_resume(struct device *dev)
 389{
 390        struct gab *adc_bat = dev_get_drvdata(dev);
 391        struct gab_platform_data *pdata = adc_bat->pdata;
 392        int delay;
 393
 394        delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
 395
 396        /* Schedule timer to check current status */
 397        schedule_delayed_work(&adc_bat->bat_work,
 398                        msecs_to_jiffies(delay));
 399        return 0;
 400}
 401
 402static const struct dev_pm_ops gab_pm_ops = {
 403        .suspend        = gab_suspend,
 404        .resume         = gab_resume,
 405};
 406
 407#define GAB_PM_OPS       (&gab_pm_ops)
 408#else
 409#define GAB_PM_OPS       (NULL)
 410#endif
 411
 412static struct platform_driver gab_driver = {
 413        .driver         = {
 414                .name   = "generic-adc-battery",
 415                .owner  = THIS_MODULE,
 416                .pm     = GAB_PM_OPS
 417        },
 418        .probe          = gab_probe,
 419        .remove         = gab_remove,
 420};
 421module_platform_driver(gab_driver);
 422
 423MODULE_AUTHOR("anish kumar <anish198519851985@gmail.com>");
 424MODULE_DESCRIPTION("generic battery driver using IIO");
 425MODULE_LICENSE("GPL");
 426
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